In September, Richardson typically sees daytime highs of 31.6°C and overnight lows around 19.2°C. Compared to the annual average high of 24.7°C, September runs +7.0°C.
September in Richardson averages a daytime high of 31.6°C and an overnight low of 19.2°C.
September runs +7.0°C compared to Richardson's annual average high of 24.7°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 31.6°C and cooler evenings around 19.2°C.